Bottom cross-over loading arm

ABSTRACT

An articulated fluid loading arm especially for transferring gasoline or other fuels from a bulk storage reservoir into the bottom of a tank truck or other fluid transport vehicle. The arm is pivotally mounted on a generally vertical riser, and includes an inboard arm section connected to the riser through a vertical swivel joint assembly, an outboard arm section connected to the inboard section through another vertical swivel joint assembly, and a coupling assembly, connected to the outboard arm section by a horizontal swivel joint assembly, for coupling the arm to the inlet of a tank or the like. The outboard arm section comprises inner and outer pipe members interconnected through a horizontal swivel joint assembly that facilitates pivoting the outer member with respect to the inner member about a horizontal axis, and the outer member and the coupling assembly are counterbalanced about this horizontal axis by a counterweight or any of several other systems including springs, fluid cylinders, and gear assemblies.

United States Patent [19] Knight 1 June 24, 1975 [75] Inventor:

[52] US. Cl. 137/615 [51] Int. Cl. Fl7d U00 1581 Field of Search137/615, 276, 279, 355.24,

[56] References Cited UNITED STATES PATENTS 3,021,867 2/1962 Gallagher137/615 X 3,086,552 4/1963 Ragsdale 137/615 3,249,121 5/1966 Bily137/615 3,587,643 6/1971 Bahr 137/615 3,678,972 7/1972 Swindler 137/615X Primary E.\'aminerCharles .1. Myhre Assistant Examiner-Ira S, LazarusAttorney, Agent, or Firm-W. W. Ritt, Jr.; C. E. Tripp 57 ABSTRACT Anarticulated fluid loading arm especially for transferring gasoline orother fuels from a bulk storage reservoir into the bottom of a tanktruck or other fluid transport vehicle. The arm is pivotally mounted ona generally vertical riser, and includes an inboard arm sectionconnected to the riser through a vertical swivel joint assembly, anoutboard arm section connected to the inboard section through anothervertical swivel joint assembly, and a coupling assembly, connected tothe outboard arm section by a horizontal swivel joint assembly, forcoupling the arm to the inlet of a tank or the like. The outboard armsection comprises inner and outer pipe members interconnected through ahorizontal swivel joint assembly that facilitates pivoting the outermember with respect to the inner member about a horizontal axis, and theouter member and the coupling assembly are counterbalanced about thishorizontal axis by a counterweight or any of several other systemsincluding springs, fluid cylinders, and gear assemblies.

9 Claims, 21 Drawing Figures 22b 26b 7 20b u PATENTEI] JUN 2 4 I975SHEET H m-HIE! SHEET PATENTEDJUN 24 I915 m mHnm-W PATENTED JUN 24 I975SHEET l FOOT FEET 2 FEET s INCHES T GRADE\ I FOOT GINCHES WVMW x F1 l3 q68 L! D a 2 1-52 /66 u Kg I @552 i u KL I W-sz 62 i Kg a 9 2 PATENTEDJUN24 I975 SHEET mm-HII HI 3 891004 JUN24|975 PATENTED SHEET 5 PATENTEIJJUN24 ms SHEET BOTTOM CROSS-OVER LOADING ARM BACKGROUND OF THE INVENTIONThis invention relates to apparatus for transferring fluid between astorage reservoir and a transport unit.

More particularly, this invention relates to tank truck' loading armsespecially for use in gasoline and other fuel service. Apparatus ofthistype may be found in the US. Pat. Nos. classified in class 137, subclass615, class 138, subclasses 107, 155 and 177, and class 141, subclasses387 and 388.

In the transfer of gasoline and other fuels as cargo into tank trucks orsimilar transport vehicles, it has been found advantageous to employarticulated pipe systems that assure no liquid or vapors will escape tothe atmosphere. Some of these pipe systems, or loading arms as they arecommonly referred to in the industry, are arranged to load the tanktruck through a manhole in its top. while others are designed forloading through an inlet at the tank's bottom. For various reasons thelatter, i.e., bottom loading, type of arm has become very popular, andits acceptance is widespread.

Certain styles of tank trucks designed for bottom loading have severalcargo compartments each of which is provided with its own inlet, therebyfacilitating loading two or more compartments simultaneously and in lesstime than if they were loaded sequentially. Such a procedure of courserequires a plurality of arms at the loading terminal, and these armsmust be arranged so that more than one can be coupled to the tank inletsand used at the same time. The location of the inlets varies fromvehicle to vehicle, and often the trucks carry more than one grade ortype of fluid. Therefore, it may not be possible to employ two or moreloading arms at one time without crossing one arm over the other. Makingsuch crossing over possible without interference between the arms, andwithout unduly restricting their operating area or envelope, arerecognized problems.

In addition to the foregoing, the matter is further complicated by tanktruck loading requirements that have had industry-wide impact. forexample such as American Petroleum Institute Specification Rp-l004, 1stEdition, October, 1967, entitled Tank Vehicle Bottom Loading andunloading". This API Specification includes requirements that a loadingterminal have up to three arms, and that the operator shall be able tocouple these arms to any two tank truck inlets on centers not less thanten inches, without doing so sequentially or in any pre-set pattern.Furthermore, the connections must be achievable without interference ofany arm at any point within a specified area or envelope, and any twoarms must be able to cross-over and be coupled to any inlet within theenvelope. Attempting to modify the previously known arms to satisfy thisspecification has given rise to problems, some of which are not solvablein a desirable manner.

SUMMARY OF THE INVENTION The present invention comprises an articulatedfluid loading arm of novel structure that permits a plurality of sucharms to be utilized in any pattern to load fluid cargo simultaneouslyinto the bottom of two or more compartments of a tank truck at a loadingterminal. The loading arm of this invention comprises an inboard armsection pivotally mounted on a generally vertical riser through a firstvertical swivel joint assembly, an

outboard arm section pivotally connected to the inboard section througha second vertical swivel joint assembly, and a coupling assemblypivotally connected to the outboard arm section through a horizontalswivel joint assembly. The outboard arm section is formed by an innerpipemember and an outer pipe member joined together through a horizontalswivel joint assembly that enables the outer member to be pivotedvertically with respect to the inner member, and in the preferredembodiment the inner member includes a horizontal component and avertical component nonrotatably interconnected through a pipe elbow. Theouter pipe member and the coupling assembly are counterbalanced aboutthe axis through the horizontal swivel joint assembly between the innerand outer members, and the means for accomplishing such counterbalancingcan comprise a counterweight assembly, a spring assembly, a fluidcylinder assembly, or a gear assembly.

When a plurality of these novel loading arms are installed together as agroup or bank, such as at "a" gasoline tank truck terminal, they aremounted at different heights on their risers so that they can bemaneuvered into various positions without interference, and the lengthof the vertical component of each outboard sections inner pipe member isappropriately sized so that each of the arms in the group can be crossedover all the others and coupled to anycargo inlet of a tank truckproperly positioned at the terminal. For example, where an installationof three arms of the invention is involved, the arms are mounted ontheir risers at three distinct heights, and the lengths of the verticalcomponents of their outboard arm sections are sized commensurately sothat the axes through the swivel joints interconnecting the inner andouter members, i.e., the counterbalance axes, are coaxial or suitablyspaced. If an installation of four arms is desired, the dimensions ofthe fourth arm can bethe same as that of the middle or second arm of thethree, and can be mounted on its riser at the same height as is thatsecond arm.

Accordingly, one object of the present invention is the provision of anew type of articulated pipe, fluid loading arm especially for use intransferring gasoline and other fluid cargo into tank trucks throughbottom located tank inlets.

Another object of the present invention is to provid a bottom loadingarm that is structured to avoid maneuvering interference with other armsof the same sytle that are mounted close together in an installation ata loading terminal.

Still another object of the present invention is the provision of abottom loading arm with a novel outboard arm section, including an outerpipe member that is pivotally secured to an inner vertical pipe memberthrough a horizontal swivel joint assembly, and that together with acoupling assembly is counterbalanced with respect to the axis throughthat swivel joint assembly.

The foregoing and additional objects and advantages of the presentinvention will become apparent from the following description and thedrawings to which it refers.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of a tanktruck loading terminal equipped with three counterweighted bottomcross-over loading arms according to the present invention, showing thearms partially extended towards a tank truck and the arms couplingassemblies positioned at three different levels. v

FIG. 2 is a plan view of the loading terminal of FIG. 1.

FIG. 3 is a diagrammatic representation. in plan, of the required APIoperating area or envelope as defined by the reach limits for bottomloading arms set forth in API Specification RP-IOO4.

FIG. 4 is a side elevation of the envelope shown in FIG. 3.

FIG. 5 is a side elevation, similar to FIG. 1, ofa four arm loadingterminal according to the present inven tion.

FIG. 6 is a rear elevation of the loading terminal of FIG. 5.

FIG. 7 is a plan view of the loading terminal of FIG. 5.

FIG. 8 is a diagrammatic representation, in plan, of four loading armsaccording to the present invention positioned for coupling to four tanktruck cargo inlets.

FIG. 9 is a fragmentary view in side elevation of the outer portion of aloading arm of this invention equipped with a tension spring assemblycounterbalancing means.

FIG. 10 is a view like FIG. 9, but showing a inder assemblycounterbalancing means.

FIG. 11 is an enlarged fragmentary view of the fluid cylinder assemblyof FIG. 10.

FIG. 12 is a view like FIG. 9, but showing a compression spring assemblysuitable for use as a counterbalancing means on a loading arm accordingto the present invention.

FIG. 13 is a fragmentary sectional view of the spring assembly of FIG.12.

FIG. 14 is a side elevation like FIG. 9, but showing a gear assemblycounterbalancing means.

FIG. 15 is an enlarged fragmentary side elevation of the gear assemblyof FIG. 14.

FIG. 16 is a fragmentary view taken along the line l6-l6 of FIG. 15.

FIG. 17 is a side elevation like FIG. 9, showing a torsion springassembly as a counterbalancing means for the loading arm.

FIG. 18 is an enlarged fragmentary view taken along the line l8-18 ofFIG. 17.

FIG. 19 is a fragmentary section taken along the line 19-19 of FIG. 18.

DESCRIPTION OF THE PREFERRED EMBODIMENT As illustrated in FIGS. 1 and 2,the preferred embodiment of a bottom cross-over loading arm 20 accordingto the present invention comprises an inboard arm section 22 pivotallymounted in a horizontal attitude on a vertical riser 24 by means of avertical pipe swivel joint 26, an outboard arm section 28 pivotallyconnected to the inboard section 22 by another vertical pipe swiveljoint 30, anda coupling assembly 32 connected to the outboard section 28by a horizontal pipe swivel joint 34, the coupling assembly 32facilitating coupling the arm to an inlet means (not shown) of agasoline or other liquid cargo tank 36 of aa transport truck 38. Theswivel joints 26,30 are oriented on vertical axes A.B, respectively,thereby enabling pivotal movement of the inboard and outboard armsections 22,28 in a horizontal direction.

The outboard arm section 28 comprises an inner pipe member 40 extendingfrom the swivel joint 30, and an outer pipe member 42 pivotallyconnected to the inner member 40 by a pipe swivel joint 44 oriented on ahorizontal axis C. The inner pipe member 40 has a horizontal component46 and a vertical component 48, these componentsinterconnected in arigid manner by a pipe elbow 50.

The outer pipe section 42 and the coupling assembly 32 arecounterbalanced about the axis C so that they can be easily placed'in adesired attitude by the loading terminal attendant or operator. and alsoto avoid imposing undesired weight on the tank truck inlets. Thiscounterbalancing can be achieved by a counterweight 52 suitably mountedon the pipe section 42 on the opposite side of the axis C (FIGS. 1 and2).

The coupling assembly 32 comprises a vertical pipe section 54 thatextends downwardly from the horizontal swivel joint 34, a verticalswivel joint 56 at the lower end of the pipe 54 and a suitable couplerdevice 58 connected to the swivel joint 56 by a pipe elbow 60. FIGS. 1and 2 illustrate a dry-break nozzle type of coupler 58 that is commonlyused in the industry for releasably connecting two pipes together. Itshould be understood, however, that other types of couplers can be employed with the loading arm of this invention, and a valve such as shownat 61 in FIGS. 9, 12, 14 and 17 can be used where its function isdesired.

As illustrated in FIGS. 1 and 2 when three of these arms 20,200,201? aregrouped together into one installation. such as at a gasoline loadingterminal, the vertical components 48,480,481) of the arms 20,20u,20b areof different lengths so that the arms can be crossed over one anotherwithout conflict. For example. should it be desired to cross loading arm200 over loading arm 20, the outboard arm section 28 of arm 20 ispivoted laterally about the axis B sufficiently to permit the verticalcomponent 48a, the outer pipe section 420. and the coupling assembly 32aof arm 20a to pass by as the arm 20:! is pivoted about its riser swivelaxis A. Likewise, arm 20/) can be crossed over arms 20 and 20a bymaneuvering the respective elements of the arms 20,20u about the axes Band B. Furthermore, arm 20a can be crossed under arm 20b byappropriately pivoting the respective elements of arm 2212 about itsaxisB". Thus, it should be quite clear that the unique structure embodied inthe loading arms 20,20a,20b facilitates cross ing them over one anotherin any order, and thus enables them to be coupled up to any transporttank inlet positioned within their functional envelope.

The arrangement of a four-arm loading terminal provides the same type ofcross-over versatility as does that of the foregoing three-arminstallation. For example. the three loading arms 62,64, and 66 of FIGS.58 are capable of crossing one another just are the arms 20,20u and 20b,and the fourth arm 68can be crossed over arms .64 and 66. This uniqueadvantage is possible because of the novel geometry of the arms of thisinvention, which geometry prevents interference between adjacent armelements as one arm is crossed over another.

In both a three-arm installation and one of four arms, the cross-overloading arm of this invention is capable of positioning the coupler 58in any location within the required operating envelope. The envelopespecified by the aforementioned API Specification RPIOO4 is an areameasuring two feet six inches in height. eight feet in width, and onefoot in depth,-and is positioned one foot six inches above grade level,allas is diagrammatically illustrated in FIGS. 3 and 4. Althoughthis isa relatively small area. it presents no problem when arms according tothe present invention are employed at the terminal.

Among the several advantages possessed by the loading arm of the presentinvention is that it is easily adaptable to various types ofcounterbalancing systems, rather than being restricted to asingle-system that might not be satisfactory as others in Certaininstallations. Although the counterweight 52 is quite adequate forproviding the required counterbalancing force, other systems such assprings, pneumatic or hydraulic cylinders, gears, etc., may be employedinstead. For example, a simple tension spring, such as that shown at 70in FIG. 9, may be connected between the vertical component 48 oftheinner pipe member 40, as by a suitable bracket 72, and the outer pipemember 42 through a bracket 74. i

The fluid cylinder arrangement illustrated in FIGS. and 11 functionsquite well as a counterbalancing system on the arm of this invention.The cylinder 76 is pivotally connected to the arms vertical component 48by a bracket 78, and its piston rod 80 is pivotally connected to theouter pipe member 42 through a suitable pin and clevis arrangement 82.Although the cylinder 76 could be operated by a pneumatic or hydraulicsystem, it will function very satisfactorily by maintaining its upperend open to the atmosphere, as by a vent 84, and pressurizing the lowerend, as through a valved inlet, until the outer pipe section 42, etc.,rise to the desired elevation. The valved line is then closed, and thefluid (air or hydraulic) in the cylinder supports these elements whilefacilitating their pivotal movement into other higher positions, such asis represented in phantom in FIG. 10.

Another type of counterbalance system for employment on the arm of thisinvention is the compression spring assembly 88 shown in FIGS. 12 and13. This assembly essentially is the same as that described in detail inUS. Pat. No. 3,086,552, issued Apr. 23, 1963 to B. P. Ragsdale, whichpatent is hereby expressly incorporated by reference, and comprises aplurality of coil springs supported in a housing by guide rods 94, and amovable pressure plate 96 through which the rods 94 extend, and to whicha chain 98 is connected, as by a rotatable sprocket 100. The housing 92is secured to the arms vertical component 48, and the outer end of thechain 98 is connected to the arm's outer pipe section 42, as through asuitable clevis assembly 102. Thus, the springs 90 support the outerpipe section 42 and coupling assembly 32 in the predesignated position.yet permit vertical pivotal movement thereof into other desiredattitudes.

A gear assembly 104 for providing the counterbalancing force for theouter pipe section 42 and coupling assembly 32 is illustrated in FIGS.14-16. This assembly comprises a housing 106 secured to the armsvertical component 48 as by a suitable bracket 108 (FIG. 16). a ringgear 110 surrounding and secured to a horizontal portion ofthe outerpipe section 42, and a pinion gear 112 in mesh with the ring gear 110and connected by a suitable gear system 114 to an external crank handle116. Thus, as the handle 116 is cranked. the pinion gear 112 rotates anddrives the ring gear 110, thereby pivoting the outer pipe section 42with respect to the 9 housing 106 and the ,arms vertical component 48. A

very satisfactory gear assembly of this type is manufactured by theBenW.Brundage Co., of Oakland, California.

Yet another springassembly for counterbalancing the outer arm section42and the coupling assembly 32 about the axis C is shown in FIGS. 17-19.This assembly 116 includes a helically-wound torsion spring 118supported in a bracket 120 that is secured to the arm s verticalcomponent 48. A lever arm 122, which issecured to one end of the spring118 and rotatablysupported in the bracket 120 by a'shaft 124, extendsfrom the bracket 120 and is pivotally connected to the outer pipesection 42 by a suitable clevis link 126 and bracket 128. The oppositeend of the spring is secured to a toothed adjustment plate 130 that canbe rotated relative to the bracket 120, andreleasably securednonrotatably to it as by a pawl 132 and bolt l34,tofacilitate adjustingthe torsional tension on the spring 118. This spring assembly is morefully described. in US. Pat. No. 3,458,167, issued July 29, 1969 to C.Cooley, .Ir., and the content thereof is expressly incorporated hereinby reference.

As will be appreciated from the foregoing, numerous advantages arepossessed by the bottom loading arm of this invention. It can be crossedover adjacent arms without interference, it has a very short outboardarm section that is quite easily maneuverable by the operator about theaxes B and C as compared with other arms where the entire arm must bemaneuvered, it has the capability of greater reach into a largeroperating envelope, and it will accept most any type of counterbalancingsystem that one might wish to employ. The eylinderbalanced version isunique in that it is actually supported on a column of air (or fluid),and this is achieved without the need for sophisticated control valves,metering devices, etc., and provides the operator with direct feel ofthe equipment without having to manipulate a control device. The arm'sgeometry enables the inboard section 22 to be positioned high enough toprovide ample headroom for the operator, and also provides leverages tomaneuver the arms elements from the ground. A minimum number of swiveljoints are employed in the arm, thereby keeping costs lower, and yetadditional swivel joints can be included if more articulation isdesired.

Although the best mode contemplated for carrying out the presentinvention has been herein shown and described it will be apparent thatmodification and variation may be made without departing from what isregarded to be the subject matter of the invention.

I claim:

1. An articulated fluid loading arm especially for use in transferringfuel from a storage reservoir into a tank truck through a bottom-locatedcargo inlet, comprising a. an inboard arm section pivotally mounted onan upstanding riser for movement with respect thereto in a horizontaldirection,

b. an outboard arm section pivotally connected to the inboard armsection for movement with respect thereto in a horizontal direction,said outboard arm section including 1. an inner horizontal pipe sectionextending from the inboard arm section,

an intermediate vertical pipe section extending downwardly from theinner horizontal pipe section, and

3. an outer pipe section pivotally connected at its inner end to-thelower 'end ofv the intermediate pipe section by a first pipe swiveljoint oriented on a horizontal axis,

c. a swivelable coupling assembly for pivotally interconnecting theouter pipe section to a bottomlocated tank truck cargo inlet. saidcoupling assembly having an inlet element and an outlet element. and

d. a second pipe swivel joint oriented on a horizontal axis andinterconnecting the outer pipe section and the coupling assembly suchthat the axis of the outer pipe section and the axis of the adjacentportion. of the coupling assembly reside in a common plane that istransverse to the axis of said second swivel joint.

2. A loading arm according to claim 1 wherein said common plane extendsthrough the area of the bearing raceway of the second swivel joint.

3. A loading arm according to claim 2 wherein the second swivel jointincludes a pair of pipe elbows extending outwardly from said bearingraceway area and wherein said elbows are flattened to reduce the widthof said second swivel joint as measured on its axis.

4. A loading arm according to claim 3 including means forcounterbalancing the outer pipe section. the second pipe swivel joint.and the coupling assembly about the horizontal axis of the first pipeswivel joint.

5. A loading arm according to claim 4 wherein the counterbalancing meanscomprises a counterweight assembly.

6. A loading arm according to claim 4 wherein the counterbalancing meanscomprises a tension spring assembly.

7. A loading arm according to claim 4 wherein the counterbalancing meanscomprises a compression spring assembly.

8. A loading arm according to claim 4 wherein the counterbalancing meanscomprises a torsion spring assembly.

9. A loading arm according to claim 4 wherein the counterbalancing meanscomprises a fluid cylinder assembly.

UNITED STATES PATENT OFFICE a. a r gCERTIFICATE OE CORRECT'IGN PATENTNO.3,891,004 v r DATED' June24, 1975,. Y

mvzmoms) HOUSTON W. KNIGHI P Y H is certified that error appears in theabove-identified pate n t arid that said Letters Patent are herebycorrected as shown below:

Column l; -'-line 5 43, "Rp" should be ..-RP [Coluinnl, V line 45"unloading" should .be Unload'-i n Column :3, line- 49; insert Figure 20is, a, w fragmentary view in side elevation, and onan. enlargedscale-,f'of 'the horizontal swivel jjoint interconnecting the outieifpipe section of' theloadingflarrn with the.

' coupling assembly. a w i. t Figure 21 is. a -v J'.e vrr, "on areducedscale, taken Y along the line 21-21 'of.,Figure '20.,,

Ii Column 3, lihei 64 "aia should "be Colnmn 4, line$28-,- insert showningeneral Figure fg i and in detail 'in Figure 21, the swivel joint 3 4*prefe rablly "is conneted to the outer pipe ,member 42 and thevertical-pipe section 54 by flattened pipe elbows "such as 150 and .-l52 to provide an -unusu ally slender-assembly that facilitatessimultaneous use' of two o1":'mo1:" e- 1 arrris ofthis] I inventi'on''in" very. tight quarters; as where th'ef-tankltr'uck' I ise spacedexceedingly close together.- Thief-feature I of the i nvention alsoenables the axis D ..(Fi'g lre "2'li)l of',the I outenlp i'pe, member.42 and the axis E of the vert' i"ca l-- pipe s e'otion' SL'tOres-ide'in'a coirunon-plan'e that is transverse? to thef-ja-xisFthrough; the swivel j'o'int s34, and in the- 'pfi e ferrediembodiment'this plan extends th;|:ou gh"the areathe bearing raoeway of this swivelfj oint -s- Signed and Scaled this sixteenth Day Of March 1976 [SEAL]Arrest:

RUTH C. MASON I C. MARSHALL DANN Arresting Officer Commissioner ufParemsand Trademarks

1. An articulated fluid loading arm especially for use in transferringfuel from a storage reservoir into a tank truck through a bottom-locatedcargo inlet, comprising a. an inboard arm section pivotally mounted onan upstanding riser for movement with respect thereto in a horizontaldirection, b. an outboard arm section pivotally connected to the inboardarm section for movement with respect thereto in a horizontal direction,said outboard arm section including
 1. an inner horizontal pipe sectionextending from the inboard arm section,
 2. an intermediate vertical pipesection extending downwardly from the inner horizontal pipe section, and3. an outer pipe section pivotally connected at its inner end to thelower end of the intermediate pipe section by a first pipe swivel jointoriented on a horizontal axis, c. a swivelable coupling assembly forpivotally interconnecting the outer pipe section to a bottom-locatedtank truck cargo inlet, said coupling assembly having an inlet elementand an outlet element, and d. a second pipe swivel joint oriented on ahorizontal axis and interconnecting the outer pipe section and thecoupling assembly such that the axis of the outer pipe section and theaxis of the adjacent portion of the coupling assembly reside in a commonplane that is transverse to the axis of said second swivel joint.
 2. anintermediate vertical pipe section extending downwardly from the innerhorizontal pipe section, and
 2. A loading arm according to claim 1wherein said common plane extends through the area of the bearingraceway of the second swivel joint.
 3. an outer pipe section pivotallyconnected at its inner end to the lower end of the intermediate pipesection by a first pipe swivel joint oriented on a horizontal axis, c. aswivelable coupling assembly for pivotally interconnecting the outerpipe section to a bottom-located tank truck cargo inlet, said couplingassembly having an inlet element and an outlet element, and d. a secondpipe swivel joint oriented on a horizontal axis and interconnecting theouter pipe section and the coupling assembly such that the axis of theouter pipe section and the axis of the adjacent portion of the couplingassembly reside in a common plane that is transverse to the axis of saidsecond swivel joint.
 3. A loading arm according to claim 2 wherein thesecond swivel joint includes a pair of pipe elbows extending outwardlyfrom said bearing raceway area and wherein said elbows are flattened toreduce the width of said second swivel joint as measured on its axis. 4.A loading arm according to claim 3 including means for counterbalancingthe outer pipe section, the second pipe swivel joint, and the couplingassembly about the horizontal axis of the first pipe swivel joint.
 5. Aloading arm according to claim 4 wherein the counterbalancing meanscomprises a counterweight assembly.
 6. A loading arm according to claim4 wherein the counterbalancing means comprises a tension springassembly.
 7. A loading arm according to claim 4 wherein thecounterbalancing means comprises a compression spring assembly.
 8. Aloading arm according to claim 4 wherein the counterbalancing meanscomprises a torsion spring assembly.
 9. A loading arm according to claim4 wherein the counterbalancing means comprises a fluid cylinderassembly.